single supply opamp

Thread Starter

asimraufawan

Joined Jul 4, 2008
29
Hi ,

i want to use LM741 opamp , do i need a dual supply or it will operate at
single supply (5v).

I want to use both inverting & noninverting input as an input & the the output will than be the analog input of PIC microcontroller.

thanks.
 

bertus

Joined Apr 5, 2008
19,944
Hello,

The LM741 needs ± 5 Volts to work.
Or 10 Volts single supply.
The LM324 works from 3 to 32 Volts single supply and contains 4 opamps.
Just take a look at the datasheet.

Greetings,
Bertus
 

Attachments

Wendy

Joined Mar 24, 2008
21,840
A better op amp for low power is the LM324 quad. It is very similar to a 741. Both aren't the best part for audio, but they do work. The LM324 is cheap, goes down to 2V power supply, and is easy to get.

Op amps as a class don't work well for digital. You need comparitors for that (LM339).
 

millwood

Joined Dec 31, 1969
0
Hi ,

i want to use LM741 opamp , do i need a dual supply or it will operate at
single supply (5v).

I want to use both inverting & noninverting input as an input & the the output will than be the analog input of PIC microcontroller.

thanks.
any opamp can work in either single rail or dual rail configurations. all you need to do is to adjust the bias on the input pins.
 

SgtWookie

Joined Jul 17, 2007
22,201
An LM741 can't get within 2v of the rails.
If you use a single 5v supply, you will have an input and output range of from 2v to 3v.

With an LM358 or LM324, maximum output will be about 3.5v with a 2k load when Vcc=5v.
 

russ_hensel

Joined Jan 11, 2009
825
YOu have to be careful not to drive the analog input below 0 ( or so ) and the PIC positive rail. One way to do this is to use a single supply rail to rail op amp with the same supply voltgage as the PIC. Op amp may not perform too well near the rails.
 
Top